1. Field of the Invention
The present invention relates to a drive transmission device that uses a planetary gear mechanism. The present invention also relates to an ink jet recording apparatus that discharges ink on a recording medium, thereby performing recording by using such a drive transmission device.
2. Description of the Related Art
Hitherto, recording apparatuses have been known which include a feeding mechanism for feeding a sheet as a recording medium to the inside thereof, a conveying mechanism for conveying the fed sheet, a recording mechanism for recording data or images on the fed sheet, and a discharge mechanism for discharging the recorded sheet outside the recording apparatus. The recording apparatuses are also provided with a drive source for operating the respective mechanisms and a drive transmission mechanism.
Among such recording apparatuses, ink jet recording apparatuses include a recording head as the recording mechanism and discharge ink on a sheet, thereby recording data or images thereon. Many of the ink jet recording apparatus are provided with a head recovery mechanism having a suction pump in order to maintain a normal ink discharge state of the recording head or recover to the normal ink discharge state in cases of clogged ink discharge ports.
As described above, a plurality of different mechanisms are mounted in the recording apparatus, and drive sources such as motors are provided in order to drive the respective mechanisms on an as needed basis. In many cases, such a recording apparatus is provided with a drive transmission switching mechanism in order to selectively transmit the drive force of one drive source to the plurality of mechanisms. A known construction of the drive transmission switching mechanism uses a planetary gear mechanism. The use of the planetary gear mechanism enables the number of drive sources or the number of drive-related components to be reduced. As a result, the ink jet recording apparatus can be manufactured at low cost and with small size, and the reliability thereof can be improved by simplifying the mechanisms.
For instance, a construction is known which uses a planetary gear mechanism so that one of two different drive transmission destinations is selected between forward rotational drive and reverse rotational drive (reference should be made, for example, to Japanese Patent No. 2,628,686). However, the above construction cannot properly perform the drive transmission if there are more than two drive transmission destinations. Moreover, in the above construction, one-directional rotational drive force can be transmitted to one drive transmission destination. However, bi-directional rotational drive force in both normal and reverse rotation directions cannot be transmitted to one drive transmission destination.
Moreover, a construction is known which uses a planetary gear mechanism that is rotated in the forward rotation direction, allowing a planetary gear to revolve and that is rotated in the reverse rotation direction, transmitting drive force to a drive transmission destination, so that drive force can be transmitted to two or more drive transmission destinations (reference should be made, for example, to Japanese Patent Application Laid-Open No. 2002-310260). However, in the above construction, only one-directional rotational drive force can be transmitted to one drive transmission destination.
Furthermore, a construction is known in which an additional drive source such as solenoid is provided exclusively for a drive transmission switching mechanism (reference should be made, for example, to Japanese Patent No. 2,855,580). The construction enables a state where a planetary gear is freely revolvable and a state where the revolving movement is restricted to be switched between, so that the drive force in both normal and reverse rotation directions can be transmitted to more than two drive transmission destinations. However, the above construction requires having a drive source exclusively for the drive transmission switching mechanism and a detector such as a sensor for detecting the revolving position of the planetary gear.
Moreover, if the number of drive transmission destinations is increased, the revolving angle of the planetary gear, when initializing the revolving position of the planetary gear, is increased. As a result, the revolving movement of the planetary gear takes time, and thus, the time taken to complete the drive transmission switching operation increases.